The Design And Fabrication Of The Rapid Adhesive Bonding Machine For Polymer Micro Devices

The adhesive bonding based on double film is a novel microfluidic technology. And it has been widely used in microfluidic devices. In this paper, an adhesive bonding machine using rational design was designed and fabricated for adhesive bonding. The main contents are as follows.(1) Mechanical structure of the bonding machine. The structure of the designed machine is comprised of rack, pressure head, guiding pillar etc. Compared with the characteristics of existing rack type, the rack of adhesive bonding machine was designed and analyzed statically using finite elements. The structure of pressure head was designed using flexible rather than rigid material. A floating joint was used as the connection between pressure head and implementation structure. The guiding structure of adhesive bonding machine was designed. Based on the characteristic of pressure head, a sliding bearing with high performance was used as guiding rod. The range of bonding pressure for this bonding machine can reach to 1.5t, and the effective bonding area of flexible pressure head is 160×160mm2.(2) The driving system and the pressure sensing unit of adhesive bonding machine. An appropriate pressure cylinder was used as implementing structure based on characteristic of adhesive bonding. A pneumatic driving system was designed, and the components of pneumatic were chosen in terms of working characteristic for pressure cylinder. The accuracy for pressure output of this adhesive bonding machine is 0.1 MPa. The precision of bonding time is Is, and the range of bonding time can reach to 30s. The pressure sensing unit was designed and built in order to meet adhesive bonding requirements. The range of pressure sensing can reach to 2t, and the accuracy of system detect is ±1kgf.(3) Experiments for adhesive bonding of polymer microfluidic chips. Bonding time and pressure were optimized with single factor test. An appropriate pressure sensitive adhesive was chosen for microfluidic chips under optimal process parameters. Then four kinds of chips were compared to analyze the influence of rigid and flexible pressure head on bonding effect under same experimental conditions. The results showed that chips had high bonding area, the cross-section of channels of chips had small deformation, and the channels were not clogged by pressure sensitive adhesive tape with flexible pressure head. The bonding strength of chips was measured. The tensile strength is 0.37MPa, and the shear strength is 1.21MPa. The leaking test of chips results showed that the chip had no leakage under 0.5MPa liquid pressure.